<!DOCTYPE html>
<head>
	<meta charset="UTF-8">
	<title>Blob showcase</title>
	<script language="javascript">
		function ShowFileType()
		{
			var file;
			file = document.getElementById("file").files[0];
			var size = document.getElementById("size");
			size.innerHTML = file.size;
			
			var type=document.getElementById("type");
			type.innerHTML = file.type;
		}
	</script>
</head>

Choose a File:
<input type="file" id="file" />
<input type="button" value="show file info" onclick="ShowFileType();" /><br/>
Size: <span id="size"></span><br/>
Type: <span id="type"></span>